As a self-luminescence element, an active matrix/organic light-emitting diode (AMOLED) is based on an OLED which is capable of emitting light due to injection and recombination of carriers occurring for an organic semiconductor material and a light-emitting material under the effect of an electric field. Due to such advantages as high brightness, high image quality, very small thickness and excellent display performance, the AMOLED tends to be widely used.
However, due to the limitation of manufacture process, the drift of a threshold voltage Vth may occur for a driving thin film transistor (TFT) of each subpixel. As a result, currents flowing through the OLEDs of the subpixels may be different from each other, and thereby a brightness difference may occur between the subpixels.